The present invention relates to a power distribution system, and in particular to a redundant power distribution system.
Typically vehicles, such as an aircraft, utilize a power distribution assembly (PDA) to distribute power to various aircraft systems. Traditionally, a PDA includes an active channel controller associated with a first power bus and a standby or back-up channel controller with a second power bus. A single arbitration card provides a communication interface for both the active and back-up channel controllers. A common data bus is connected to each of the power modules and interfaces with the arbitration card. When healthy, the active channel controller provides power from the first power bus to the plurality of power modules or loads, while the back-up channel controller remains in a stand-by mode, providing no power from the second power bus to the loads. In the event the first channel controller fails, or the first power bus becomes unhealthy, the arbitration card switches control from the active channel controller to the back-up channel controller, which distributes power from the second power bus to the plurality of loads.
In this way, the traditional redundant architecture provides the requisite reliability for critical systems. However, this architecture requires that each power bus be capable of handling loading requirements for all attached loads. As such, circuit breakers or other protective devices associated with both the first and second power buses must be sized to handle the full loading requirements of each of the plurality of loads. The combined power rating of the circuit breakers is therefore underutilized during normal operation in which both or all power buses are healthy.